[Incidence of Secondary Malignancy of Chronic Myeloid Leukemia during Treatment of Breast Cancer with Hormone Therapy].

It is expected that the number of long-term breast cancer survivors will increase owing to the improvements in chemotherapy and irradiation, while the risk of double cancers, including secondary malignancy, may become an issue. There are many unclear points in the treatment policy with regard to when a secondary malignancy occurs or the primary cancer relapses during the management of a secondary malignancy. A 54-year-old woman who was diagnosed with ER/PgR-positive HER2 negative breast cancer Stage ⅢB received neoadjuvant chemotherapy FEC and docetaxel followed by breast surgery, adjuvant hormone therapy, and radiation therapy. Chronic myeloid leukemia diagnosed by the abnormal findings of leukocytosis and bone marrow aspiration emerged after 3 years of the diagnosis of the first breast cancer. After 3 years of imatinib therapy that achieved a major molecular response(MMR)of CML, a recurrence of sacral metastasis of breast cancer was revealed by MRI. The combination of imatinib and hormone or S-1 chemotherapy could be maintained without serious adverse events after the relapse of the primary cancer.